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© Georg Thieme Verlag Stuttgart New York – Synform 2015/08, A116–A118 Published online: July 20, 2015 DOI: 10.1055/s-0034-1380870 Literature Coverage Synform A116 Palladium-Catalyzed Enantioselective Synthesis of P-Stereogenic Compounds via C–H Arylation Angew. Chem. Int. Ed. 2015, 54, 6265–6269 Chiral phosphine compounds are extremely useful ligands in catalysis. However, phosphorus (P)-chiral ligands have not been explored as extensively in catalytic reactions as axially chiral, carbon (C)-chiral, or planar-chiral compounds such as binap, diop, or josiphos. This is probably because P-chiral compounds are less easily available and more difficult to syn- thesize than other types of chiral compounds. Asymmetric ca- talysis has the potential to provide a more direct and efficient synthetic route compared to traditional resolution methods of constructing P-chiral compounds. Scheme 1 Construction of P-chiral compounds through enantioselective C–H arylation Scheme 2 Enantioselective C–H arylation of diarylphosphinic amides

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  • © Georg Thieme Verlag Stuttgart • New York – Synform 2015/08, A116–A118 • Published online: July 20, 2015 • DOI: 10.1055/s-0034-1380870

    Literature CoverageSynform

    A116

    Palladium-Catalyzed Enantioselective Synthesis of P-Stereogenic Compounds via C–H Arylation

    Angew. Chem. Int. Ed. 2015, 54, 6265–6269

    Chiral phosphine compounds are extremely useful ligands in catalysis. However, phosphorus (P)-chiral ligands have not been explored as extensively in catalytic reactions as axially chiral, carbon (C)-chiral, or planar-chiral compounds such as binap, diop, or josiphos. This is probably because P-chiral

    compounds are less easily available and more difficult to syn-thesize than other types of chiral compounds. Asymmetric ca-talysis has the potential to provide a more direct and efficient synthetic route compared to traditional resolution methods of constructing P-chiral compounds.

    Scheme 1 Construction of P-chiral compounds through enantioselective C–H arylation

    Scheme 2 Enantioselective C–H arylation of diarylphosphinic amides

    http://dx.doi.org/10.1002/anie.201500201

  • © Georg Thieme Verlag Stuttgart • New York – Synform 2015/08, A116–A118 • Published online: July 20, 2015 • DOI: 10.1055/s-0034-1380870

    Literature CoverageSynform

    C–H bond functionalization has been an extremely po-pular topic over the past decade, and numerous methods based on a C–H bond activation strategy have been develop-ed to build diverse complex molecules from unfunctional-ized materials. The group of Professor Wei-Liang Duan at the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (P. R. of China) has a longstanding interest in both the asymmetric synthesis of chiral phosphorus compounds (J. Am. Chem. Soc. 2010, 132, 5562; Org. Chem. Front. 2014, 1, 541) and C–H bond functionalization reactions (J. Am. Chem. Soc. 2013, 135, 16754). Professor Duan said: “We asked ourselves the question of whether the enantioselective C–H arylation stra-tegy could be utilized for the synthesis of useful P-stereogenic compounds (Scheme 1).”

    Professor Duan explained: “Initially, ortho-bromophenyl diphenylphosphinate was chosen as the model substrate for palladium-catalyzed intramolecular C–H arylation reactions; however, formation of racemic products – with no enantio-control – was observed with several ligands examined (Syn-thesis 2014, 46, 1067).” He continued: “Then, diarylphosphinic amides were prepared and investigated under palladium ca-talysis and using various chiral phosphine ligands. Finally, the use of a Taddol-based dimethylaminophosphoramidite ligand successfully generated an array of P-stereogenic compounds with up to 93% ee (Scheme 2).”

    It is worth pointing out that the P–N bond of the products can be cleaved with alkyllithium reagents, and P-chiral mono-phosphine oxides were obtained without erosion of enantio-selectivity (Scheme 3).

    Professor Duan concluded: “Now, we are trying to syn-thesize P-chiral biaryl monophosphine ligands based on the developed protocols, and we hope that the resulting P-chiral phosphines can be utilized as efficient ligands in some asym-metric reactions.”

    A117

    Scheme 3 Preparation of chiral biaryl monophosphine oxides from the obtained P-chiral compounds

    About the authors

    Ziqi Lin received her BSc degree from Shandong University (P. R. of China) in 2010. She later joined the research group of Professor Weiliang Duan and is currently a PhD student at Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (P. R. of China).

    Weizhen Wang was born in Anhui (P. R. of China) in 1990. He received his BSc degree from Hubei University (P. R. of China) in 2013 and is now working with Professor Weiliang Duan for his Master’s degree at Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (P. R. of China).

    Shaobai Yan was born in Hunan (P. R. of China) in 1989. He received his BSc degree (under the supervision of Professor Yuefa Gong) from Huazhong University of Science and Tech-nology (P. R. of China) in 2012. Currently, he is a postgraduate student (under the supervision of Professor Weiliang Duan) at Shanghai Institue of Organic Chemistry, Chinese Academy of Sciences (P. R. of China).

    From left: S. Yan, Prof. W. Duan, W. Wang, Z. Lin

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    http://dx.doi.org/10.1021/ja100606vhttp://dx.doi.org/10.1021/ja100606vhttp://dx.doi.org/10.1039/C4QO00017Jhttp://dx.doi.org/10.1021/ja407373ghttp://dx.doi.org/10.1021/ja407373ghttp://dx.doi.org/10.1055/s-0033-1340832http://dx.doi.org/10.1055/s-0033-1340832

  • © Georg Thieme Verlag Stuttgart • New York – Synform 2015/08, A116–A118 • Published online: July 20, 2015 • DOI: 10.1055/s-0034-1380870

    Literature CoverageSynform

    A118

    Weiliang Duan received his PhD in chemistry in 2007 from Kyoto University (Japan) under the guidance of Professor Tamio Hayashi. He then carried out postdoctoral work in the labo-ratory of Professor Scott E. Denmark (University of Illinois at Urbana Champaign, USA). In 2008, he joined the Shanghai In-stitute of Organic Chemistry, Chinese Academy of Sciences (P. R. of China) as an associate professor. In 2014, he was pro-moted to professor. His research focuses on transition-metal-catalyzed C–H bond activation and the development of chiral ligands for asymmetric catalysis.